Gas liquefying apparatus



Feb. 10, 1959 c. o. JONKERS EI'AL 2,

GA LIQUEFYING APPARATUS Filed Jan. 12. 1955 INVENTORS CORNELIUS OTTO JONKERS JACOB WILLEM LAURENS KOHLER BYM AGENT United States Patent GAS LIQUEFYING APPARATUS Cornelius Otto Junkers and, Jacob Wiliem Laurens Kiihler, Emmasingel, Eindhoven, Netherlands, assignors, by mesne assignments, to North American Philips Company, Inc., New York, N. Y., a corporation of Delaware Application January 12, 1955, Serial No. 481,406

Claims priority, application Netherlands January 15, 1954 4 Claims. (Cl. 61-6) The invention relates to a cold-gas refrigerator suitable for condensing a gaseous mixture, the condensation taking place on at least one wall associated with the freezer, a second wallb'eing provided, by means of which one or more condenser spaces extending in a vertical direction are formed.

A cold-gas refrigerator is often also termed a refrigerator operating on the reversed hot-gas engine principle. It is known that these machines may be constructed in various ways, for example as a displacer-piston machine, as a double-acting machine, as a machine, the cylinders of which are atan angle to one another, or as amachine of which the working space is combined with that of a hot-gas engine. By means of these refrigerators a large temperature difference can be. bridged in one step. The refrigerator may for example yield a cold of -1 0O C. and even -200 C. The machines may therefore be used to condense various gases and gaseous mixtures.

A cold-gas refrigerator, comprising a condenser space has already been proposed in which a gaseous mixture is condensed. With the refrigerator proposed the gaseous mixture to be condensed is supplied to the condenser space from the top side,so that both the gaseous mixture and the condensate produced flow downwards. if the gaseous mixture contains components which are condensed with difiiculty, which may often be the case, these components will accumulate at the top end of the condenser space, so that the operation of the refrigerator is affected adversely.

it has now been found that it is desirable that the gaseous mixture to be condensed should enter in accordance with the invention, only from the bottom side of the condenser space, the mixture then rising upwards in the condenser space, while at the top end of this space provision is made of means by which the non-condensed gases are conducted away.

With the cold-gas refrigerator according to the invention the gaseous mixture to be condensed thus rises during the condensationup along the wall of the freezer, while the condensateflows down against the rising flow of the gaseous mixture. Thus the gaseous mixture is separated to some extent into fractions, while at the top end of the condenser space the non-condensed components are accumulated. These components may afterwards be conducted away from the space. If these noncondensed gases would not be conducted away, the condenser space would contain a comparatively large volume of these gases after some time. The condensible gases would thus not be in thermal contact with the wall of the freezer or come into contact herewith only to a smaller extent so that the temperature of the freezer would drop below the operational temperature which would affect adversely the production of the machine.

For structural reasons it is often desirable to supply the gases to be condensed nevertheless from the top side. In one embodiment of the invention provision may be 2,872,789 Patented Feb. 10, 1959 made in this case not only of the condenser space but also of one or more spaces which communicate at the top end with the supply duct for the gaseous mixture and at the bottom end with the condenser space. By

means of this construction a rising flow of the gases inthe condenser spaces is obtained.

In a further embodiment of the invention the condenser space is surrounded by a subdivided or not subdivided, annular space which serves as a communication between the supply ducts and the condenser space.

The non-condensed gases may be conducted away in various ways, for example by means of a pump. Accord ing to a further aspect of the invention, in case of a cold-gas refrigerator, the cooler of which is cooled by means of cooling water, the non-condensed gases are sucked away by a water-jet air pump. This water-jet air pump may be driven by the cooling water of the refrigerator.

According to a further aspect of the invention, the duct between the water-jet pump and the condenser space includes a part having such a contracted passage that the velocity of the drained gases is such that penetration of water vapour through the duct is avoided at least for the major part. With this construction a maximum of V of the quantity of gas supplied to the refrigerator can he conducted away by the water-jet air pump, if the cold-gas refrigerator condenses air, While nevertheless the velocity of the drained gas may be sufficient to prevent water vapour from penetrating.

In certain cases it may be desirable to conduct away the gases to be drained in a counter flow to the gaseous mixture to be condensed so that this gaseous mixture is preceded by the drawn-off gases.

The cold-gas refrigerator according to the invention may include various kinds of freezers. The freezer may, for example, be constructed in the form of a pipe freezer.

As an alternative the freezer may be constructed as a heat exchanger provided with vanes and surrounding the freezing space concentrically, this freezer being surrounded by an annular space subdivided by vanes or not subdivided, through which the gaseous mixture to be condensed can rise upwards.

According to a further aspect of the invention an annular duct is provided at the bottom end of the condenser space, this duct serving to collect the condensate produced in this space. The condensate collected in the annular duet can then be conducted away from the system.

The invention will be described more fully with reference to the drawing illustrating the embodiment thereof.

The single figure shows a cold-gas refrigerator comprising a cylinder it in which a displacer-piston 2 and a piston 3 are adapted to move up and down with substantially constant phase difference. To this end they are coupled each by way of a connecting-rod system 4 and 5 respectively with cranks of a crank shaft 6. The space 7 above the displacer-piston Z is the low-temperature space, the so-called freezing space, whereas the space 8 between the displacer-piston 2 and the piston 3 is the high-temperature space, the so-called cooled space. The two spaces communicate with one another by way of a freezer or low temperature heat absorber 9, a regenerator l0 and a cooler or high temperature heat rejector 11. The refrigerator is driven by an electric motor 12. The space in which the gases are condensed is constituted by the space 13 provided inside a Wall 14. The wall 14 compels the gaseous mixture to be condensed to rise up along a wall 35 having vanes 16 of the freezer 9, the gaseous mixture thus condensing and the condensate flows downwards. The gaseous mixture is supplied through an opening 17 to the cold-gas refrigerator and flows first through a space 18 downwards and then rises up in the space 13. The condensate produced is collected in an annular duct 19 and conducted away from the refrigerator through a duct 20.

At the top end of the space 13 provision is made of a tube 21, provided with apertures. By way of a duct 22, having a contraction 23, this tube communicates with a water-jet air pump 24, which is driven by cooling water for the refrigerator, which flows out of the cooler 11 through a duct 25. The cooling water is supplied to the cooler through a duct 26.

It should be apparent that in the space 13 formed by wall 14 unliquified gases such as nitrogen and helium will accumulate. This is undesirable since an increasing quantity of unliquified gases will reduce the workable surface area of the freezer. These unliquified gases are drawn off through duct 22 to form a jet in pump 24 which evacuates the same into the atmosphere without permitting penetration of the Water vapor through the duct 22.

In the figure the cold-gas refrigerator is constructed in the form of a displacer-piston machine. As stated above, the refrigerator may be constructed in different ways. Moreover, the freezer of the refrigerator may be constructed in a different way. There is a possibility to subdivide the space 13 into a plurality of spaces, each of which may have an individual draining device owing to the presence of the vanes 16 on the wall 14.

What is claimed is:

1. A cold-gas refrigerator being capable of condensing a gaseous mixture comprising a cylinder, two pistons in said cylinder, means operating said pistons in said cylinder with a constant phase difference, said two pistons and cylinder defining two chambers; a high temperature heat rejector for one of said chambers, a regenerator, and a low temperature heat absorber for the other of said two'chambers, a gaseous medium of invariable chemical composition within the cylinder, the volume of the gaseous medium in said chambers varying continuously while one of the chambers has a low temperature whereby a closed thermodynamic cycle is performed therein, a housing spaced from and surrounding said heat absorber and provided with an opening therethrough, a wall in said housing adjacent to said heat absorber having a flanged end part extending substantially parallel to the longitudinal axis of said heat absorber, said wall forming at least one condenser space extending in a substantially verticaldirection, said gaseous mixture supplied through said opening entering said condenser space at the bottom thereof, and means in the top of said condenser space for conducting away non-condensed gases of said gas mixtures, and a drain in the bottom of said housing for drawing off the condensate in said condenser.

2. A cold-gas refrigerator as set forth in claim 1 further comprising means for cooling said heat rejector by water, and said cooling means including a water-jet air pump for drawing off non-condensed gases of said gaseous mixture from said condenser space.

3. A cold-gas refrigerator as set forth in claim 2 further comprising a duct between said water-jet air pump and said condenser space having a part thereof with a restricted passage whereby the velocity of the drawn-off gases is such that the penetration of water vapor through the duct to the condenser space is substantially avoided.

4. A cold-gas refrigerator as set forth in claim 1 further comprising an annular collecting duct in the bottom of said condenser space connected to said drain whereby condensate produced in said space is collected. 

